The invention relates to a method of designing tires having improved noise characteristics, in particular in relation with the first cavity mode frequency.
Cavity mode noise regularly causes difficulties to car manufacturers. As cars are to be more and more quiet, the noise generated by the resonance frequency of the air contained in the tire cavity becomes increasingly undesirable.
Different types of solutions have been developed by different manufacturers to reduce the cavity noise and/or other type of noise. For example, such solutions may use the following features:                foam material on rim;        Helmholtz or quarter-wave resonators either placed in the wheel or in an insert provided in the wheel cavity.        
Most of the known solutions seem to give positive test results. However, they all require an additional element inside the tire/wheel assembly, or modifications of the wheel/rim assembly. A solution which would avoid using such an additional component or such a modification, would therefore be seriously considered by car manufacturers.